Cytokeratin expression patterns in jaw cyst linings with metaplastic epithelium

Cysts and Pseudocysts of the Oral Cavity: Revision of the Literature and a New Proposed Classification

This article includes a comprehensive and up-to-date review on the cysts of the oral cavity. Several classifications of odontogenic (OC) and non-odontogenic (non-OC) oral cysts and the surrounding regions have been proposed. We suggest a new critical classification based on an established relationship between anatomical area, histological origin and clinical behavior (frequency, rate of recurrence, malignant potential). Moreover, the differential cytokeratin (CKs) expression of the various cysts is reported as epithelium-specific markers of differential diagnosis. Finally, issues related to differential diagnosis and therapeutic approaches of the cysts included in the two groups are described.

A Comparative Analysis of Cytokeratin 18 and 19 Expressions in Odontogenic Keratocyst, Dentigerous Cyst and Radicular Cyst with a Review of Literature

INTRODUCTION

Odontogenic cysts viz Odontogenic Keratocyst (OKC), Dentigerous Cyst (DC) and Radicular Cyst (RC) occur commonly in the oral and maxillofacial region. Cytokeratin (CK) expression studies have been done to evaluate diagnostic accuracy, role in pathogenesis, elucidate behaviour and role in treatment protocols. However, variations have been reported in the expression of CK patterns in these odontogenic cysts, which could be due to the lack of standardization of laboratory techniques. The present study has tried to shed light on CK 18 and 19 expression in odontogenic cysts and offer the brief review of previous studies on these CK.

AIM

The aim of the present study was to evaluate the intensity and expression patterns of CK 18 and 19 in OKCs, DCs and RCs.

MATERIALS AND METHODS

A total of 60 cases, 20 each of OKC, DC and RC were confirmed histologically and evaluated for immunohistochemical expression pattern and intensity of CK 18 and 19.

RESULTS

A focal and variable expression of CK 18 was observed in 25% of OKCs, 15% of DCs and 10% of RCs. CK 19 was expressed in 75% of OKCs and 100% in DCs as well as RCs.

CONCLUSION

The intensity and expression of Cytokeratin 19 was more in all three cysts compared to Cytokeratin 18.

Cytokeratin expression patterns for distinction of odontogenic keratocysts from dentigerous and radicular cysts

BACKGROUND

The clinical outcome of treatment of odontogenic cysts differs depending on separate entities. Particular clinical relevance must be attached to the distinction between odontogenic keratocysts, which have an evident tendency to recur, and other odontogenic cysts. The aim of this study was to evaluate cytokeratin (CK) expression patterns as an additional tool for characterization of different cysts as the histomorphologic appearance often is not decisive.

METHODS

Thirty cases of dentigerous and radicular cysts respectively as well as 15 cases of odontogenic keratocysts were considered. Expression of CK 5/6, 7, 10, 13, 17, 19 and 20 was determined in addition to Ki-67 immunohistochemically.

RESULTS

Expression of CK 17 was discernible in 93.3% of the odontogenic keratocysts, but only in 35.0% of dentigerous and radicular cysts under study (P < 0.001). CK 19 could be detected in 48.3% of dentigerous and radicular cysts, whereas odontogenic keratocysts were completely negative (P < 0.002).

CONCLUSION

Immunohistochemical detection of CK 17 and 19 seems to be a valuable additional parameter distinguishing between odontogenic keratocysts and other odontogenic--especially dentigerous--cysts which clinically are likely the most significant differential diagnoses in this context. J Oral Pathol Med (2005) 34: 558-64.

Expression of cytokeratins (CKs) 8, 13 and 18 and their mRNA in epithelial linings of radicular cysts: implication for the same CK profiles as nasal columnar epithelium in squamous epithelial lining

OBJECTIVE

Our objective was to specify cytokeratin (CK) patterns in lining epithelia of radicular cysts which are sometime lined with ciliated columnar epithelia as seen in the nasal epithelia.

MATERIALS AND METHODS

We examined the CK expression in 52 radicular cysts obtained from 32 maxillary and 20 mandibular lesions and investigated CK-mRNA expression using in situ hybridization in 24 maxillary and 13 mandibular cysts and reverse transcription-polymerase chain reaction (RT-PCR) in 24 maxillary cysts.

RESULTS

Of the maxillary cysts, 20, 29 and 19 squamous epithelial linings were positive for CK8, CK13 and CK18, respectively; of the mandibular cysts, 10, 20 and 11 linings were positive for these CKs, respectively. The expression patterns of CK18(+)-CK13(-), CK18(+)-CK13(+) and CK18(-)-CK13(+) were observed in 3, 16 and 13 linings of the maxillary cysts and 0, 11 and 9 linings of the mandibular cysts, respectively. In situ hybridization revealed the expression of CK18-mRNA in 9 and 4 linings of 24 maxillary and 13 mandibular cysts examined, respectively. With RT-PCR, we explored that both CK18- and CK13-mRNA were expressed not only in the normal nasal and gingival epithelia but also in the examined maxillary cyst linings although their expression levels differed correlating with the difference in CK staining.

CONCLUSION

It is concluded that CK13- and CK18-mRNA are constitutively expressed in columnar and squamous epithelial cells, respectively, and that the variant CK expression patterns with CK18-mRNA expression in maxillary radicular cysts are indicative of the possibility of phenotypic transformation in the cyst linings.